U.S. Pat. No. 4,775,658 is directed to a silane copolymer combined with a colloidal silica and a releasing agent to form a network structure in the thermal dye receiving sheet. There is no disclosure in this patent, however, that such a combination would be useful as a subbing layer in a dye-donor element. Moreover, there is no disclosure in that patent that teaches or suggests the use of a metal alkoxide with a copolymer in the subbing layer.
U.S. Pat. No. 4,737,486 is directed to a dye donor element for thermal dye transfer. The dye donor comprises a polymeric support having a subbing layer and a dye layer comprising a dye dispersed in a binder. The subbing layer comprises a polymer having an inorganic backbone which is an oxide of Group IVa or IVb element. There is no disclosure in this patent, however, that teaches or suggests the use of a combination of a metal alkoxide with a copolymer having an alkoxysilane component in the subbing layer.